Research progress of terahertz sensor based on artificial microstructure

Recently, terahertz(THz) technology has developed rapidly, showing promising potential in the fields of communication, anti-terrorism, monitoring and biomedicine, etc. In particular, terahertz biosensor has attracted extensive attentions in biotechnology, because many biological molecules and materials have their finger prints in the THz absorption spectra, and the damage by the low power terahertz wave is low. However, the THz wave-matter interaction is relatively weak because of the mismatch between the long wavelength of THz wave and the size of biomolecules, which limits the performance of terahertz sensors. Current research interest is manipulating the spatial and spectral distributions of the electromagnetic fields based on the microstructures to enhance the sensitivity of the sensors. In this review, we are going to introduce the working mechanisms of various microstructure THz sensors and the recent progress, and then discuss their advantages and disadvantages, finally we conclude the major issues to be resolved and predict the future developing trend and potential applications.